I have looked all over for the answer to this question, so I apologize if I missed it, but, what is the proper way to use reserves after a player has missed hi invite?

1. Send an invite to the first reserve (potentially slows the process another 24 hours)2. Send a PM with the password to all reserves informing them "first in wins the spot"? (potentially fills the spot immediately)

Invite reserves one at a time based on the order they signed up. Many of the early reserves may have signed up for the tournament before it was updated to Full status, so they deserve the first shot at open spots.

In general I go one by one down the list of reserves. There are some tournaments, however, that are better fits for different reserves, for instance, in cases where the players are ranked by point level and seeded, it can be fairly important to have a reserve that is close to the player being replaced if possible.